Electric motor with split pole pieces



Oct. 7, 1952 H. A. sHuMAKEiQ ETAL 2,513,242

ELECTRIC MOTOR WITH SPLIT POLE PIECES Filed Feb. 10 1949 2 SHEETS-SHEET l c Oct. 7, 1952 H. A. SHUMAKER ET AL 2,613,242

ELECTRIC MOTOR WITH SPLIT POLE PIECES Filed Feb. 10, 1949 2 SHEETS-SHEET 2 66 32/72 53 If, III/V X:

47 hvenz'zs Howard A. Skzmm/zei" /37 3 and Z Zgya/P 724F726! Wfaeoo 3y I Patented Oct. 7, 1952 1 UNITED STATES PATENT OFFICE ELECTRIC MOTOR WITH semi. POLE rnicss Howard A. Shumaker, Amhe t, O and Edgar .1. Turner, .Fanwood, N. .J., assignors to The Singer Manufacturing .Companr, Elizabeth.

.L, a corporation of New Jersey Application February 10, 1949, Serial N 0, 75,552

.7 Glaims. (Cl 172- 278) The present invention relates to electric motors especially adapted, though not necessarily restricted, for use in ambulatory type vacuum cleaners, and the invention has for one of its pri- The vacuum cleaner, per se, is equipped with a rotary dust brush |8supported on arms |9-|-9, and driven by a belt 2]. A propelling handle 22 which carries a cord reel 23, as fully set forth "mary objects to provide an improved motor and in patent application Serial No. 64,736 supra, is method of constructing the same. secured to and pivots with the upper and lower Anotherchject of the invention is to provide motonfan frames I4 and I3. an improved field pole clamping means for elec- In addition to the previousl described upper trio motors. and lower motor frames 14 and 3, the motor-fan Another object of the invention is to provide unit includes a unitary rotating element 24 coma new andimprcved method of assembling an prising a shaft 26 carrying, at its mid-point, an electric motor. armature 21 and associated commutator '28. Each Astlll further object of the invention is to proend of the shaft 26 is equipped with a suction vide an improved means for accurately locating fan -29 and one end of the shaft is extended to and holding the field pole pieces .of an electric form a driving pulley 3| for the belt 2|. Adjamotor... cent each fan, the shaft carries 'a ball bearing The invention comprises the devices, combina- 32 of which the outer race rings are each adapted tier-land arrangement of parts hereinafter deto be fitted (Fig. 3) into a semi-circular bearing scribed in connection with the accompanying socket 33 formed in the lower frame I 3. The ball drawings, which illustrate a preferred embodibearings 32 are held in their respective sockets ment of the. invention and in which: 33 by clamps 34 and screws 36. By reason of Fig. l isfa plan view of a portion of a vacuum this construction, the unitary rotating element cleaner. showing the motor of this invention, part '24 may be assembled and dynamically balanced pf the .motor frame and vacuum cleaner shell apart from the rest of the motor. The previously being removed to show the internal construction, balanced rotating element 24 may be inserted Fig. 2 is a fragmentary sectional view taken into the lower motor frame l3 without having substantially. along the line 2-4 of Fig. 1, to balance it after it is installed. A motor coolvFig. 3 is a fragmentary sectional view taken ing fan 3'1, of known construction, is secured to on the line 3-3 of Fig. 1, the shaft 26 at a location between the armature Flash, 5 and 6 are schematic diagrams show- 21 and one of the bearings 32. Also a pair of ing some of the elements shown in Fig. 2 and of brushes 38-38, that may be of known con- .illustratihg the method of installing the lower struction, are supported by boxes-39--39 in such pole piece, a manner as to engage the commutator 28. J Fig. 7 is a fragmentary view particularly illus- A split pole piece 4|, which forms the magnetic tratins the method of installing the upper pole circuit for the field portion of the motor, compiece, and prises a pair of identical U-shaped structures,

Fig. 8 is a reduced scale view of a dummy manhaving arm portions 42 and 43; and a connectdrel used to position the lower pole piece. ing bridge 44. The U-shaped structures are des- Referring more specifically to the drawings, ignated in the drawings as lower pole piece' ll' theinvention is disclosed as embodied in an 40 and upper pole piece 4|". The pole piece 4|, as electric motor and fan unit mounted in a vacua whole, is supported by the lower motor-fan um cleaner of the type described in patent applihousing I3 by means presently to be described. cation'Serial No. 64,736, filed December 11, 1948, Each pole piece 4| and 4|" is constructed from and, having a lower casing shell H which is a plurality of soft iron laminations clamped toadapted to be covered by an upper casing shell, -5 gether by rivets 46, in a known manner. The not herein shown but fully illustrated in the connecting core or bridge 44 of each U-shaped patent application Serial No. 64,736 supra. Held member 41' and 4|" is surrounded by and thus clampedbythe upper and lower casing shells are sup orts afield coil 41. Each arm 42 and 43 of flanged'irings |2|2 and these rings pivotally the two pole pieces 4| and 4|"is cut away on support asplit, combination motor-fan housin acurve 48, of which the radius is slightly greater or frame comprising a lower, motor-fan frame than the radius of the armature 21, thereby member [31 and a complemental upper, motorpermitting the pole pieces to span the armature if an fram e member I4, the upper motor-fan frame 21 with sufficient clearance to provide a proper :rnemberbeing held to the lower frame member air gap 49 (Fig. 2). The base of each arm 42 by screws 16 and I1. and 43 is provided with a depression 5| the purpose of which will hereinafter be explained. The end (Fig. '7) of each arm 42 has a point 52, which when the two pole pieces are assembled, as shown in Fig. 2, enters a V-shaped notch 53 formed on the end of the arm 43. Reference to Fig. 2 of the drawings shows that the lower pole piece 4|, when installed inthe frame |3|4, is positioned with its arms 4243 upstanding, whereas, the pole piece 42" is inverted with its arms 42-43 depending.

The upper pole piece 4| is held (Fig. 2) to the lower pole piece 4| by a pair of substantially Z-shaped spring clips or hold-down clamps 54-54. held to the lower motor frame I3 by means of a screw 55 threaded into a hole 5'5. The upper end of each clip 54 is fashioned into a hook 58 for engaging the depressions 5|5| formed in the upper pole piece 4|. Each clip 54, intermediate its ends, carries a U-shaped guard 59 of such size and shape as to just fit over the joint 52--53 between the upper and lower pole pieces 4|" and 4| and thus assure proper alignment of the pole pieces in a direction longitudinally of the shaft 26.

The lower pole piece 4| is located in the lower motor-fan frame |3 so as to have the cutaway surfaces 48 truly coaxial with the bearing sockets 3333 in the lower motor frame l3 by a method which comprises placing (Fig. i) the lower pole piece 4| in the lower motor frame I3 and resting on seat 53 therein, but with the lower core 4| below its proper position. Then placing, in the bearing sockets 33-33 of the lower half of the motor frame, a dummy unit or mandrel 54 (Figs.-5 and 8) having a shaft 26 and a pair of bearings 32 --32 that are identical in size with the shaft bearings 32-32 carried on the motorfan shaft 26. The mandrel 64 instead of having an armature secured between the two bearings 32 -32 is provided with a cylindrical magnet 66, of which the diameter is larger than the diameter of the armature 21 by an amount equal to'the air gap 49 normally desired between the armature 21 and pole pieces 4| and 4|". When this magnet is in place and supportedby its bearings 32 32 from the bearing sockets 33-33, it lifts by magnetic force, (Fig. 5) the lower pole piece 4| from the seat 63 and holds it truly coaxial with the axis of rotation of the armature 27. When this has been accomplished, the space (Fig. 6) between the lower motor frame l3 and the lower pole piece 4| is temporarily filled with clay or other suitable flowable material, as indicated at 68. When the lower pole piece 4| is properly positioned, molten metal or other suitable flowable material 59 is poured into the space between the bottom of the lower pole piece 4| and the seats $3 provided in the lower half of the motor frame l3. When the molten metal 69 has solidified, it holds the lower half of the pole piece in its proper working position coaxial with the axis of the motor shaft. The dummy mandrel 64 is then removed and replaced by the prebalanced rotating unit 24 of the motor.

The preferred method of installing the upper pole piece 4|" is indicated in Fig. 7, wherein the spring clips 5454 are shown sprung sufficiently to allow the upper pole piece 4! to be shoved down between the hooks 5858. It Will be apparent that when the points 5252 engage the notches 5353 that the hooks 58-58 will enter the depressions 5|5l in the upper pole piece 4|", as shown inFig. 2. When this has been accomplished, the other motor parts including the The lower bent end of each clip 54 is 4 brushes 38, the brush boxes 39, the belt 2|, upper motor frame |4 etc. can easily and quickly be installed.

Electrical conductors for connecting the cord reel 23 to an external source of electric power, to the brushes 38-48, and to the field coils 41-41 of the motorare not shownandjit. will be understood that any proper and well known electrical connections may be used. Having thus set forth the nature of the invention, what we claim is:

1. A split frame electric motor comprising a lower frame, a lower pole piece supported by an internal portion of said lower frame, an upper pole piece identical in form to said lower pole piece, a pair of spring clips carried by said lower frame, and a hook on the upper end of each of said spring clips, said hooks engaging said upper pole piece and thereby holding said two pole pieces together. 1

2. A split frame electric motor comprising a lower frame member, a U-shaped pole piece supported from said lower-frame member and having a pair of upstanding arms, an armature rotatably supported'from said lower franie' member and positioned between said upstanding arms,'a U-shaped pole piece having depending arms resting on the upstanding arms of said lower pole piece, a pair of spring clips secured to'saidlower frame, a hook on the upper end of each 'ofsaid spring clips, said hooks engaging said'upper pole piece, a pair of U-shaped guards carried by' each of said spring clips, said'guards spanning the arms of said pole pieces, and an upper frame member secured to said lower frame member."

3. A split frame electric motor comprising a. lower-frame, a complemental upper fran'ie secured to said lower-frame, an armature enclosed by said frames and rotatably supported by said lower-frame, a pair of identical pole pieces having matching in and notched endsand the'reby fitted together and arranged to encompass said armature, and means for securing both ofsaid 'pole pieces to the lower frame, includinga pair of Z-shaped spring clips secured to saidlower frame and engaging said upper pole piece.

4. A split frame electric motor comprising, a lower frame member, a U-shaped lower pole piece having one pin ended armand]. one; notch ended arm, a thermoplastic material interposed between the bottom of said lower pole piece and said frame member, an inverted U-shaped upper pole piece having one pin ended arm and one notch ended arm placed. upon said lower pole piece, and hooks carried by said lower frame member and engaging said upper pole piece; whereby said pole pieces are clamped to said lower frame member. r l A 5. A split frame electric motor, comprising, a separate lower-frame member, a separate U shaped lower pole piece carried bys'aid, lower frame member, an inverted U-shaped upper pole piece placed upon said lower pole piece, saidupper pole piece being identical with said lower pole piece and hold-downs having lower. portions secured solely to said lower frame member and having upper portions engaging solely said upper pole piece, thereby forcing said upperpolepiece against said lower pole piece, and said'lower pole piece against said lowerframe-member. jl

6. A'split frame electric motor, comprising'a separate lower-:frame member, a separate U,- shaped lower pole piece carriedbyjsaid' lower frame member and having a pair of upwardly extending arms, a point on the end of one of said arms and a notch on the end of the other of said arms, an inverted separate U-shaped upper pole piece having a pair of downwardly extending arms, a point on the end of one of said down- Wardly extending arms and a notch on the end of the other of said downwardly extending arms, said upper pole piece being identical with said lower pole piece and being placed upon said lower pole piece, and hold-downs having lower portions secured-solely to said lower frame member and having upper portions engaging solely said upper pole piece, thereby forcing said upper pole piece against lower pole piece, and'said lower pole piece against said lower frame member.

7. A split frame electric motor, comprising, a separate lower-frame member, a separate U- shaped' lower pole piece, an inverted separate U- shaped upper pole piece having a pair of depressions in one end thereof and placed upon said lower pole piece, said upper pole piece being identical with said lower pole piece, and means having one end secured to said frame member and having the other end entering said depressions in said upper pole-piece and thereby holding both of said pole pieces to said lower-frame member.

HOWARD A. SHUMAKER. EDGAR P. TURNER.

REFERENCES CITED The following references are of record in the file of this patent: 

